Hydrocracking process

Abstract

Methods of hydrocracking hydrocarbon streams are provided that employ substantially liquid-phase continuous hydroprocessing conditions. In one aspect, the method includes a separate hydrotreating and hydrocracking system where the hydrocracking zone is a substantially liquid-phase continuous system. In another aspect, the method includes a two-stage hydrocracking system where one or both of the hydrocracking zones is a substantially liquid-phase continuous reaction system.

1. A method of hydrocracking a hydrocarbonaceous stream comprising:
 providing a hydrocarbonaceous feed stock having a boiling point range; 
 directing the hydrocarbonaceous feed stock to a hydrotreating zone to produce a hydrotreating zone effluent; 
 directing the hydrotreating zone effluent to a separation zone to separate one or more lower boiling point hydrocarbon streams from a higher boiling point liquid hydrocarbon stream; 
 taking at least a portion of the higher boiling point liquid hydrocarbon stream as a hydroprocessing feed; 
 admixing an amount of hydrogen with the hydroprocessing feed such that substantially liquid-phase conditions are maintained; 
 directing the hydroprocessing feed to a substantially liquid-phase continuous hydrocracking zone; and 
 reacting the hydroprocessing feed substantially undiluted with another hydrocarbon stream in the substantially liquid-phase continuous hydrocracking zone with a hydrocracking catalyst under hydrocracking conditions to produce a hydrocracking zone effluent having hydrocarbons with a lower boiling point range relative to the higher boiling point liquid hydrocarbon stream. 
 
     
     
       2. The method of  claim 1 , wherein the amount of hydrogen added to the hydroprocessing feed is in excess of that required for saturation of the hydroprocessing feed. 
     
     
       3. The method of  claim 2 , wherein the amount of hydrogen added to the hyroprocessing feed is up to about 1000 percent over that required for saturation of the hydroprocessing feed. 
     
     
       4. The method of  claim 1 , wherein the hydrogen added to the hydroprocessing feed is provided from a make-up hydrogen system. 
     
     
       5. The method of  claim 1 , wherein the substantially liquid-phase continuous hydrocracking zone operates without a recycle gas compressor. 
     
     
       6. The method of  claim 1 , wherein the hydrotreating zone is a gas-phase continuous reaction zone. 
     
     
       7. The method of  claim 1 , wherein the separation zone includes a high pressure separation zone upstream of a fractionation zone, and wherein the hydrotreating zone effluent is directed to the high pressure separation zone and the hydrocracking zone effluent is also directed to the high pressure separation zone. 
     
     
       8. The process of  claim 7 , wherein the fractionation zone separates light hydrocarbons boiling in the range from about 4° C. (40° F.) to about 93° C. (200° F.), naphtha boiling hydrocarbons boiling in the range from about 32° C. (90° F.) to about 260° C. (500° F.), distillate boiling hydrocarbons boiling in the range from about 149° C. (300° F.) to about 385° C. (725° F.), and the higher boiling point liquid hydrocarbon stream boiling in the range from about 326° C. (650° F.) to about 593° C. (1100° F.). 
     
     
       9. A method of hydrocracking a hydrocarbonaceous stream comprising:
 providing a hydrocarbonaceous feed stock having a boiling point range; 
 directing the hydrocarbonaceous feed stock to a hydrotreating zone to produce a hydrotreating zone effluent; 
 directing at least a portion of the hydrotreating zone effluent to a first hydrocracking zone with a hydrocracking catalyst and operated under hydrocracking conditions to produce a first hydrocracking zone effluent; 
 separating the first hydrocracking zone effluent into one or more lower boiling point hydrocarbon streams and a higher boiling point liquid hydrocarbon stream in a separation zone; 
 taking at least a portion of the higher boiling point liquid hydrocarbon stream as a hydroprocessing feed; 
 adding an amount of hydrogen to the hydroprocessing feed such that substantially liquid-phase conditions are maintained; 
 directing the hydroprocessing feed to a substantially liquid-phase continuous hydrocracking zone; and 
 reacting the hydroprocessing feed substantially undiluted with another hydrocarbon stream in the substantially liquid-phase continuous hydrocracking zone with a hydrocracking catalyst under hydrocracking conditions to produce a second hydrocracking zone effluent having hydrocarbons with a lower boiling point range relative to the higher boiling point hydrocarbon stream. 
 
     
     
       10. The method of  claim 9 , wherein the amount of hydrogen admixed with the hydroprocessing feed is in excess of that required for saturation of the hydroprocessing feed. 
     
     
       11. The process of  claim 9 , wherein the amount of hydrogen added to the hydroprocessing feed is up to about 1000 percent over that required for saturation of the hydroprocessing feed. 
     
     
       12. The process of  claim 9 , wherein the amount of hydrogen is provided from a make-up hydrogen system. 
     
     
       13. The method of  claim 9 , wherein the substantially liquid-phase continuous hydrocracking zone operates without a recycle gas compressor. 
     
     
       14. The method of  claim 9 , wherein the hydrotreating zone is a gas-phase continuous reaction zone. 
     
     
       15. The method of  claim 9 , wherein the first hydrocracking zone is a gas-phase continuous hydrocracking zone. 
     
     
       16. A method of hydrocracking a hydrocarbonaceous stream comprising:
 providing a hydrocarbonaceous feed stock having a boiling point range; 
 directing the hydrocarbonaceous feed stock to a hydrotreating zone to produce a hydrotreating zone effluent having a gas-phase and a liquid-phase; 
 separating the gas-phase from the liquid-phase; 
 adding an amount of hydrogen to the liquid-phase such that substantially liquid-phase conditions are maintained; 
 directing the liquid-phase to a first substantially liquid-phase continuous hydrocracking zone, the liquid-phase substantially undiluted with another hydrocarbon stream, and the first substantially liquid-phase continuous hydrocracking zone operated under hydrocracking conditions to produce a first hydrocracking zone effluent; 
 separating the first hydrocracking zone effluent into one or more lower boiling point hydrocarbon streams and a higher boiling point liquid hydrocarbon stream in a separation zone; 
 adding an amount of hydrogen to the higher boiling point liquid hydrocarbon stream such that substantially liquid-phase conditions are maintained; 
 directing the higher boiling point hydrocarbon stream to a second substantially liquid-phase continuous hydrocracking zone, the higher boiling point hydrocarbon stream substantially undiluted with another hydrocarbon stream; and 
 reacting the higher boiling point hydrocarbon stream in the second substantially liquid-phase continuous hydrocracking zone with a hydrocracking catalyst under hydrocracking conditions to produce a second hydrocracking zone effluent having hydrocarbons with a lower boiling point range relative to the higher boiling point hydrocarbon stream. 
 
     
     
       17. The method of  claim 16 , wherein the amount of hydrogen added to the hydrotreating zone effluent is up to about 1000 percent over that required for saturation of the hydrotreating zone effluent. 
     
     
       18. The method of  claim 16 , wherein the amount of hydrogen added to the hydrotreating zone effluent is provided from a make-up hydrogen system. 
     
     
       19. The method of  claim 16 , wherein the separation zone includes a high pressure separation zone upstream of a fractionation zone, and wherein the first hydrocracking zone effluent is first directed to the high pressure separation zone and the second hydrocracking zone effluent is also directed to the same high pressure separation zone. 
     
     
       20. The process of  claim 19 , wherein the fractionation zone separates light hydrocarbons boiling in the range from about 4° C. (40° F.) to about 93° C. (200° F.), naphtha boiling hydrocarbons boiling in the range from about 32° C. (90° F.) to about 260° C. (500° F.), distillate boiling hydrocarbons boiling in the range from about 149° C. (300° F.) to about 385° C. (725° F.), and the higher boiling point liquid hydrocarbon stream boiling in the range from about 326° C. (650° F.) to about 593° C. (1100° F.).